In case your instance is stopped or failed, restarting or relaunching your instance will end up with a different public IP address. This becomes inconvenient if users have to change the address for accessing JupyterHub. This section will demonstrate the proper set-up for allocating a static IP address to your AWS instance. For this purpose, an Elastic IP address can be allocated to your account and asociated with an instance, so that users can always access your JupyterHub with the same IP.
Navigate to the Elastic IP configuration on the AWS EC2 Console. Opt to allocate an elastic IP address from Amazon's pool of IPv4 addresses. Then, choose to associate this new address and select your instance. The Elastic IP is now your instance's public IP.